President Donald J. Trump’s decision to withdraw from the Iran nuclear deal will have very serious consequences for the Middle East and for Iran itself, as well as upcoming US negotiations with North Korea. It will also add severe new tensions to an already strained transatlantic alliance and place many Central and East European countries in an untenable situation.

Several European countries, after signing the Joint Comprehensive Plan of Action (JCPOA) in 2015, have secured infrastructure, transport and energy agreements with Iran worth billions of dollars. Iran, an unexplored and hungry market of over 80 million consumers, is too precious to be abandoned easily.

Trump’s decision has broken the unity and cohesion of the transatlantic community. The Americans will withdraw from the agreement, while the Europeans will try to remain committed. This is a highly dangerous precedent, especially at a time when both sides of the Atlantic are facing a variety of threats requiring mutual consent, cooperation and solidarity.

If Europe remains committed to the JCPOA, would Trump not be tempted to punish its disloyalty, for example, by reducing pressure against Russia? Furthermore, the political position of smaller European states is now very difficult.

Poland can serve as an example here. It was not party to the nuclear negotiations, nor does it play any significant role in the geopolitical struggle in the Middle East. But Poland, like various other Central and East European states, can support just one of two camps – either the West Europeans, their partners in the European Union, or the United States, their major NATO ally and security provider.

By supporting the United States, they will worsen their relations with the EU. By doing the opposite, they might provoke Trump into punishing them. This could be done, for example, by withdrawing the US troops protecting Poland, Lithuania, Latvia, Estonia, Romania and Bulgaria against Russia.

Of course, Trump might postpone the implementation of Iran sanctions just as he has postponed the implementation of punitive tariffs against the EU in the trade dispute, but this seems rather unlikely given his tough rhetoric against Tehran on May 8.

Undoubtedly, the destruction of the JCPOA would also have significant consequences for Iran itself. The nuclear deal and its expected economic outcomes were the cornerstone of the political campaign of President Hassan Rouhani and his camp of pro-Western pragmatists. Without the JCPOA, the Iranian president would be seriously weakened and humiliated. Not only might he lose any chance he might have had to become Iran’s next Supreme Leader, but he also might be impeached.

The death of the JCPOA will increase the power of the conservatives, for whom any negotiations with the United States were doomed to failure from the beginning. Trump’s decision will give this camp more power soon, if Rouhani is impeached, or after the next parliamentary and presidential elections in 2020 and 2021, respectively. If the JCPOA dies, Iran’s next president is likely to be similar to former president Mahmoud Ahmadinejad – a confrontational, anti-Western hardliner.

For ordinary Iranians, the consequences look especially bleak.

Millions of Iranians had hoped that the nuclear agreement would give them a better life and a chance to catch up with the rest of the world. They thought that the JCPOA would be the first step on the way to normalizing Iran’s relations with the West and potentially the United States. These hopes have been dashed once again.

Of course, it is not only Trump who should be blamed – the Islamic Republic has had trouble attracting foreign investment because of inadequate protections for intellectual property, rampant corruption and a lack of transparency in the way decisions are made. Unfortunately, Trump’s actions give the government a ready scapegoat for its failures.

If the JCPOA ultimately collapses, even the most moderate and open-minded of Iranians will have no argument to counter the statement that negotiations with the United States, now or in the future, do not make any sense because the Americans will sooner or later go back on their word.

Robert Czulda is is an Assistant Professor at the University of Lodz, Poland and a former visiting professor at Islamic Azad University in Iran, the University of Maryland and National Cheng-chi University in Taiwan. He is the author of “Iran 1925 – 2014: Between Reza Shah and Hassan Rouhani.”